Temperature is a key measurement parameter in controlling the quality of glass or glass products. Inline (fixed) thermal imaging cameras or non-contact infrared temperature sensors can be installed that measure the temperature of glass products and surfaces during production, as well as glass substrates used in semiconductor processing and for the manufacture of solar cell panels, automotive glass, glass containers/tubes, light bulbs and LCD displays. However, current thermal imaging technology is limited in the accuracy it can achieve.
With a spectral range of 7.9µm, the thermoIMAGER G7 accurately measures the temperature of the glass, even very thin glass. Conventional thermal imagers with spectral wavelengths of 8-14µm do not measure accurately the temperature of the glass. At longer wavelengths, glass allows transmission of temperature from objects behind or near to the glass, which gives inaccurate measurements, normally lower than the true glass temperature. Using the G7 camera at a wavelength of 7.9µm eliminates any transmission from other objects, resulting in very accurate glass temperature measurement.
Chris Jones, Managing Director at Micro-Epsilon UK, comments: “When measuring at 7.9µm, the glass object becomes a solid body and only emits its own temperature. This results in very accurate temperature measurements, even on very thin glass or thin walled objects such as glass tubes, bottles and substrates.”
Even if the glass has a protective (reflective) coating applied to it, an additional reference pyrometer can be set up to provide an adjustment factor to the camera, which corrects for this reduction in transmission of infrared temperature from the glass – a unique feature of the thermoIMAGER software supplied as standard with the G7.
Like all thermoIMAGER TIM thermal imaging cameras, the G7 is supplied with full, licence-free operating and analysis software, which includes a variety of process control features such as ‘line scan mode’ – a feature that enables the camera to view through a narrow slit (restricted field of view) onto the glass, yet still provide a complete thermal image of the entire sheet.
Powered and operated via a USB 2.0 interface, the G7 provides temperature images and profiles of a target area. This plug-and-play unit enables the real time capture (at 80Hz full frame rate) and storage of images or video of an event for slow motion play back or snapshots at a later date – a key feature in many quality, inspection, R&D and failure diagnostics work.
The G7 is lightweight (320g) and compact (46 x 56 x 90mm) and operates in ambient temperatures of 0°C to +70°C (+240°C with an integrated cooling jacket).
An alternative method of measuring the temperature of glass and glass products is to use a high precision infrared temperature sensor.